Comment by drob518

Those are exotic parts that would have to be manufactured specially. You don’t buy them off the shelf. They are costly to procure and difficult to work with. One doesn’t just load up the 3d printer and push Go. To be clear, I’m sure a homemade gun can be passed through a metal detector checkpoint, but that requires some real thought and skill. More than likely, the real weak link at the checkpoint is not the detector “seeing” the gun but the half-asleep agent missing it, given the red-teaming results which show even very traditional firearms have a good chance of slipping through.